Chuyển tiếng Việt có dấu sang không dấu

Ứng dụng của hàm này thường dùng trong những trường hợp sau:

• Tạo URL thân thiện
• Tạo Desciption tối ưu bộ tìm kiếm

C# - Cách 1

private static readonly string[] VietNamChar = new string[]
{
    "aAeEoOuUiIdDyY",
    "áàạảãâấầậẩẫăắằặẳẵ",
    "ÁÀẠẢÃÂẤẦẬẨẪĂẮẰẶẲẴ",
    "éèẹẻẽêếềệểễ",
    "ÉÈẸẺẼÊẾỀỆỂỄ",
    "óòọỏõôốồộổỗơớờợởỡ",
    "ÓÒỌỎÕÔỐỒỘỔỖƠỚỜỢỞỠ",
    "úùụủũưứừựửữ",
    "ÚÙỤỦŨƯỨỪỰỬỮ",
    "íìịỉĩ",
    "ÍÌỊỈĨ",
    "đ",
    "Đ",
    "ýỳỵỷỹ",
    "ÝỲỴỶỸ"
};
public static string utf8Convert1(string str)
{
    //Thay thế và lọc dấu từng char
    for (int i = 1; i < VietNamChar.Length; i++)
    {
        for (int j = 0; j < VietNamChar[i].Length; j++)
            str = str.Replace(VietNamChar[i][j], VietNamChar[0][i - 1]);
    }
    return str;
}

C# - Cách 2

public string utf8Convert(string s)
{
    string stFormD = s.Normalize(NormalizationForm.FormD);
    StringBuilder sb = new StringBuilder();
    for (int ich = 0; ich < stFormD.Length; ich++)
    {
        System.Globalization.UnicodeCategory uc = System.Globalization.CharUnicodeInfo.GetUnicodeCategory(stFormD[ich]);
        if (uc != System.Globalization.UnicodeCategory.NonSpacingMark)
        {
            sb.Append(stFormD[ich]);
        }
    }
    sb = sb.Replace('Đ', 'D');
    sb = sb.Replace('đ', 'd');
    return (sb.ToString().Normalize(NormalizationForm.FormD));
}

C# - Cách 3

public static string utf8Convert3(string s)
{
    Regex regex = new Regex("\\p{IsCombiningDiacriticalMarks}+");
    string temp = s.Normalize(NormalizationForm.FormD);
    return regex.Replace(temp, String.Empty).Replace('\u0111', 'd').Replace('\u0110', 'D');
}

JavaScript

function utf8ConvertJavascript(obj)
{
    var str;
    str = str.toLowerCase();
    str = str.replace(/à|á|ạ|ả|ã|â|ầ|ấ|ậ|ẩ|ẫ|ă|ằ|ắ|ặ|ẳ|ẵ/g, "a");
    str = str.replace(/è|é|ẹ|ẻ|ẽ|ê|ề|ế|ệ|ể|ễ/g, "e");
    str = str.replace(/ì|í|ị|ỉ|ĩ/g, "i");
    str = str.replace(/ò|ó|ọ|ỏ|õ|ô|ồ|ố|ộ|ổ|ỗ|ơ|ờ|ớ|ợ|ở|ỡ/g, "o");
    str = str.replace(/ù|ú|ụ|ủ|ũ|ư|ừ|ứ|ự|ử|ữ/g, "u");
    str = str.replace(/ỳ|ý|ỵ|ỷ|ỹ/g, "y");
    str = str.replace(/đ/g, "d");
    str= str.replace(/!|@|%|\^|\*|\(|\)|\+|\=|\<|\>|\?|\/|,|\.|\:|\;|\'| |\"|\&|\#|\[|\]|~|$|_/g,"-");
    /* tìm và thay thế các kí tự đặc biệt trong chuỗi sang kí tự - */
    str= str.replace(/-+-/g,"-"); //thay thế 2- thành 1-
    str = str.replace(/^\-+|\-+$/g, "");

    return str;
}

SQL Server - Cách 1

CREATE FUNCTION [dbo].[utf8ConvertSQL]
(
@strInput nvarchar(4000)
)
RETURNS nvarchar(4000)
AS
BEGIN
SET @strInput = RTRIM(LTRIM(LOWER(@strInput)));
IF @strInput IS NULL
BEGIN
RETURN @strInput;
END;
IF @strInput = ''
BEGIN
RETURN @strInput;
END;
DECLARE @text nvarchar(50), @i int;
SET @text = '-''`~!@#$%^&*()?><:|}{,./\"''='';–';
SELECT @i = PATINDEX('%['+@text+']%', @strInput);
WHILE @i > 0
BEGIN
SET @strInput = replace(@strInput, SUBSTRING(@strInput, @i, 1), '');
SET @i = PATINDEX('%['+@text+']%', @strInput);
END;
SET @strInput = replace(@strInput, ' ', ' ');

DECLARE @RT nvarchar(4000);
DECLARE @SIGN_CHARS nchar(136);
DECLARE @UNSIGN_CHARS nchar(136);
SET @SIGN_CHARS = N'ăâđêôơưàảãạáằẳẵặắầẩẫậấèẻẽẹéềểễệế
ìỉĩịíòỏõọóồổỗộốờởỡợớùủũụúừửữựứỳỷỹỵý'+NCHAR(272)+NCHAR(208);
SET @UNSIGN_CHARS = N'aadeoouaaaaaaaaaaaaaaaeeeeeeeeee
iiiiiooooooooooooooouuuuuuuuuuyyyyy';
DECLARE @COUNTER int;
DECLARE @COUNTER1 int;
SET @COUNTER = 1;
WHILE(@COUNTER <= LEN(@strInput))
BEGIN
SET @COUNTER1 = 1;
WHILE(@COUNTER1 <= LEN(@SIGN_CHARS) + 1)
BEGIN
IF UNICODE(SUBSTRING(@SIGN_CHARS, @COUNTER1, 1)) = UNICODE(SUBSTRING(@strInput, @COUNTER, 1))
BEGIN
IF @COUNTER = 1
BEGIN
SET @strInput = SUBSTRING(@UNSIGN_CHARS, @COUNTER1, 1) + SUBSTRING(@strInput, @COUNTER+1, LEN(@strInput)-1);
END;
ELSE
BEGIN
SET @strInput = SUBSTRING(@strInput, 1, @COUNTER-1) + SUBSTRING(@UNSIGN_CHARS, @COUNTER1, 1) + SUBSTRING(@strInput, @COUNTER+1, LEN(@strInput)-@COUNTER);
END;
BREAK;
END;
SET @COUNTER1 = @COUNTER1 + 1;
END;
SET @COUNTER = @COUNTER + 1;
END;
SET @strInput = replace(@strInput, ' ', '-');
RETURN LOWER(@strInput);
END;

SQL Server - Cách 2

CREATE FUNCTION [dbo].[GetUnsignString]
(
@strInput nvarchar(4000)
)
RETURNS nvarchar(4000)
AS
BEGIN
IF @strInput IS NULL
BEGIN
RETURN @strInput
END;
IF @strInput = ''
BEGIN
RETURN @strInput
END;
DECLARE @RT nvarchar(4000);
DECLARE @SIGN_CHARS nchar(136);
DECLARE @UNSIGN_CHARS nchar(136);
SET @SIGN_CHARS = N'ăâđêôơưàảãạáằẳẵặắầẩẫậấèẻẽẹéềểễệếìỉĩịíòỏõọóồổỗộốờởỡợớùủũụúừửữựứỳỷỹỵýĂÂĐÊÔƠƯÀẢÃẠÁẰẲẴẶẮẦẨẪẬẤÈẺẼẸÉỀỂỄỆẾÌỈĨỊÍÒỎÕỌÓỒỔỖỘỐỜỞỠỢỚÙỦŨỤÚỪỬỮỰỨỲỶỸỴÝ'+NCHAR(272)+NCHAR(208);
SET @UNSIGN_CHARS = N'aadeoouaaaaaaaaaaaaaaaeeeeeeeeeeiiiiiooooooooooooooouuuuuuuuuuyyyyyAADEOOUAAAAAAAAAAAAAAAEEEEEEEEEEIIIIIOOOOOOOOOOOOOOOUUUUUUUUUUYYYYYDD';
DECLARE @COUNTER int;
DECLARE @COUNTER1 int;
SET @COUNTER = 1;
WHILE(@COUNTER <= LEN(@strInput))
BEGIN
SET @COUNTER1 = 1;
WHILE(@COUNTER1 <= LEN(@SIGN_CHARS) + 1)
BEGIN
IF UNICODE(SUBSTRING(@SIGN_CHARS, @COUNTER1, 1)) = UNICODE(SUBSTRING(@strInput, @COUNTER, 1))
BEGIN
IF @COUNTER = 1
BEGIN
SET @strInput = SUBSTRING(@UNSIGN_CHARS, @COUNTER1, 1) + SUBSTRING(@strInput, @COUNTER+1, LEN(@strInput)-1);
END
ELSE
BEGIN
SET @strInput = SUBSTRING(@strInput, 1, @COUNTER-1) + SUBSTRING(@UNSIGN_CHARS, @COUNTER1, 1) + SUBSTRING(@strInput, @COUNTER+1, LEN(@strInput)-@COUNTER);
END;
BREAK;
END;
SET @COUNTER1 = @COUNTER1 + 1;
END;
SET @COUNTER = @COUNTER + 1;
END;
RETURN @strInput;
END;